Setback switch



1947- J. w. BUSACKER ETAL SETBACK SWITCH Filed Aug. 5, 1945 FIG. 2.

MN I

IN RS JOHN w BUSA axe-R R z. MANE'VAL ATTORNEY Patented Nov. 18, .1947

SETBACK SWITCH John W. Busacker and Richard L. Maneval, Houston, Tex., assignors to the United States of America, as represented 'by the Secretary of the Navy Application August 3, 1943, Serial No. 497,230

4 Claims.

1 This invention relates to a switch, and more particularly to an electrical switch which may be mounted within a projectile to close at least a portion of an electrical detonating circuit when 2 underlies the rear or bottom end of the contact member Hi and wedges the latter against the shoulder IS, The bar It may be formed as an integral part of a post I1. The post I! is provided the projectile is fired. 5 with an internally threaded portion I8, and is An object of the invention is to provide a switch secured to the body member It by means of a of the character indicated which will remain in screw threaded bolt I9 which extends through a opened position during normal handling of the bore in the body It]. Thus, one side of the circuit explosive projectile in which the same is mounted, extends from the battery B to post I1, through bar and which will be automatically actuated to close 10 i5 and then to contact member It. upon the application of setback force created by The bore I2 has an enlarged portion or recess the acceleration of the projectile when the same 28 formed in its forward or upper end thereof, .is fired from a gun. the recess 2%! defining a shoulder 2!. A disc 22, Other objects of the invention are to provide a preferably of metal, is mounted within the recess setback switch which may be easily made and 5 29 and. rests on shoulder 2!, the disc 22 having a assembled and wherein the numerous mechanical centrally positioned aperture therein for receivoperating parts usually employed in prior art dcing a hollow stud 23, a wire 24, which forms the vices of this nature have been eliminated. other side of circuit C, extends through the aper- Still other objects of the invention will be apture in disc 22 and into the bore I2. The stud .parentfrom the following description of the draw- 23 and disc 22 rigidly support wire 24 to the ings, in which: upper portion of stem II, as shown in Figs. 2 Fig. 1 is a longitudinal sectional view of aporand 3. The wire 24 has a plurality of coils or tion of a projectile and a diagrammatical view of convolutions 25 therein, and its end is soldered the switch mounted therein, the switch being in or otherwise secured at 26 to the bottom of an corporated within an electrical detonating cir- 25 elongated substantially U-shaped contact sleeve cuit. 27. The contact sleeve 21 is formed of suitable Fig. 2 is an enlarged sectional View of the switch conductive metal and is loosely mounted within when in its opened position, bore I2 for longitudinal movement therein. Seal- Fig. 3 is an enlarged sectional view of the 30 ing wax or the like, 28, is placed in recess 20 over switch when in its closed position. disc 22 to seal the latter within the stem II.

Referringnow to the drawings, and particularly The wire .26 is of suitable gauge so that, when Fig. 1 thereof, the letter P generally indicates shortened by the convolutions 25, it will support a portion of a projectile which has at least a contact sleeve 21 in the upper or forward portion portion of an electrical detonating circuit C of bore I2 in spaced relation to the stationary therein. The circuit C is provided with a battery contact member I4, as shown in Fig. 2. The parts B or other suitable source of current. will remain in this position under normal han- The body of the device it is formed of insudling-of the projectile in which they are mounted, lating material, and may be a portion of a body thereby maintaining the electrical detonating cirof an amplifier or other component within the cuitC opened. projectile. An upstanding sleeve II is formed 40 The operation of the switch will be readily integrally with the body Ill and has a bore I2 apparent from the foregoing description. When extending therethrough. The bore I2 is prothe parts are in the position shown in Fig. 2, the vided with an enlarged portion I3 at its rear or switch is opened and circuit C is broken. When lower end, the enlarged portion I3 defining a the projectile is fired, the acceleration thereof shoulder I3. A cup-shaped contact member M, creates a setback force which is sufiicient to throw formed of suitable conductive metal, is mounted the contact sleeve 21 rearwardly against the tenin the enlarged portion I3 of the bore 12 and bears sion of the convolutions 25 formed in wire 24. As against the shoulder I3. The contact member Id the contact sleeve 2'! slides rearwardly in bore l2, has an annular inwardly flared portion I5 adjait forms a clinch type of contact with contact cent to the forward or top portion thereof. It member I 4 by contacting the annular inwardly will be noted that the diameter of the inwardly flared portion I5, as shown in Fig. 3. The wire 24 flared portion I5 of contact member M is slightly is sufficiently ductile so that when the convoluless than the diameter of bore I2. The contact tions 25 are partially pulled out to elongate the member I4 is secured within the enlarged portion wire, the convolutions will stay in their extended I3 of bore I2 by means of a metallic bar It which positions and will not tend to urge the contact an electrical detonating circuit upon the appli- V cation of setback force created when the projectile is fired comprising a body member of insulating material having a stem extending therefrom, a bore in said body member extending through said stem, said bore having an enlarged portion adjacent to one end thereof, a stationary cylindrical contact member having an annular inwardly flared portion mounted in said enlarged portion of said bore, a contact sleeve positioned in said bore capable of sliding therein upon the application of setback force created when the projection is fired, and means for maintaining said sleeve in spaced relation with said stationary contact member until setback force is created and for permitting said sleeve to slide into engagement with said annular inwardly flared portion of said stationary contact member after setback force is created, said means including an extendible member secured to said sleeve.

2. A setback switch adapted to be mounted within a projectile to close at least a portion of an electrical detonating circuit upon the application of setback force created when the projectile is fired comprising a body member of insulating material having any integral stem extending therefrom, a bore in said body member extending through said stem, said bore having an enlarged portion adjacent to one end thereof, a stationary cylindrical contact member having an annular inwardly flared portion mounted in said enlarged portion of said bore, a contact sleeve positioned in said bore capable of sliding therein upon the application of setback force created when the projectile is fired, and means including a wire forming a portion of the electrical detonating circuit having one end secured to said sleeve for maintaining said sleeve in spaced relation with said stationary contact member until setback force is created and for permitting said sleeve to slide into engagement with said annular inwardly flared portion of said stationary contact member after setback force is created.

3. A setback switch adapted to be mounted within a projectile to close at least a portion of an electrical detonating circuit upon the application of setback force created when the projectile is fired comprising a body member of insulating material having an integral stem extending therefrom, a bore in said body member extending through said stem, said bore having an 4 enlarged portion adjacent to each end thereof, a stationary cylindrical contact member having an annular inwardly flared portion mounted in one of said enlarged portions of said bore, a disc having an aperture therein mounted in the other enlarged portion of said bore, a contact sleeve positioned in said bore capable of sliding therein upon the application of setback force created when the projectile is fired, and means for maintaining said sleeve in spaced relation with said stationary contact member until setback force is created and for permitting said sleeve to move into engagement with said stationary contact member after setback force is created, said means including a wire which forms a portion of the electrical detonating circuit having a plurality of convolutions therein, said wire extending through the aperture of said disc into said bore and being secured at its end to said contact sleeve.

4. A setback switch adapted to be mounted within a projectile to closeat least a portion of an electrical detonating circuit upon the application of setback force created when the projectile is fired comprising a body member of insulating material having an integral stem extending therefrom, a bore in said body member extending through said stem, said bore having an enlarged portion adjacent to each end thereof, a stationary cylindrical contact member having an annular inwardly flared portion mounted in one of said enlarged portions of said bore, means including a part of the electrical detonating circuit for securing said contact member within said bore, a disc having an aperture therein mounted in the other enlarged portion of said bore, a contact sleeve positioned in said bore capable of sliding therein upon the application of setback force created when the projectile is fired, and means for maintaining said sleeve in spaced relation with said stationary contact member until setback force is created and for permitting said sleeve to move into engagement with said stationary contact member after setback force is created, said means including a wire which forms a portion of the electrical detonating circuit having a plurality of convolutions therein, said wire extending through the aperture in said disc into said bore and being secured at its end to said contact sleeve.

JOHN W. BUSACKER. RICHARD L. MANEVAL.

REFERENCES CITED The following references are of record in the file of this patent:

FOREIGN PATENTS Number Country Date 602,624 France Aug. 25, 1925 728,341 France Dec. 16, 1931 

